Electric reciprocating tool



H. N. MARVIN. ELECTRIC REGIPRDGATING TOOL.

(No Model.)

No. 420,080. Patented Jan. 28, 1890.

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UNITED STATES HARRY N. MARVIN, OF SYRACUSE, NE\V YORK.

ELECTRIC RECIPROCATING TOOL.

SPECIFICATION forming part of Letters Patent No. 420,080, dated January28, 1890.

Application filed April 29, 1889. Serial No. 309,132. (No model.)

To all whom it hwy concern.-

Be it known that I, HARRY N. MARVIN, a citizen of the United States,residing in Syracuse, in the county of Onondaga, in the State of NewYork, have invented certain new and useful Improvements in ElectricReciprocating Tools, of which the-following is a specification.

My invention relates to the construction and organization of apparatusfor producing reciprocating movements by means of electricity.

The object of my invention is to provide a system for operatingreciprocating tools that shall be simple in construction and operationand capable of being operated upon existing electric circuits.

In the construction of tools of this character it has been customary toemploy two solenoids or electro-magnets adapted to impart by theiralternate action a reciprocating movement to the tool. In the operationof such tools it has been customary to shift the current abruptly fromcoil to coil by some form of circuit-controllen I have found that whilesuch devices may answer where the amount of energy thus shifted isslight and the coils employed are small, when it is desired to employlarge electro-magnets and great amounts of energy it is very desirableto give to the current an undulatory or pulsatory characterthat is tosay, to admit to the coil first an extremely small amount of energy andto gradually increase this current until a maximum is reached, when thecurrent is as gradually reduced to a minimum again. To accomplish this Ihave resorted to the plan for which I seek a patent.

The following is a description of my invention,reference being made tothe accompanying drawings, in which= Figure 1 is a diagram showing adiagram of a source of electric currents, a section of a reciprocatingtool, and a top view of the circuit-controller. Fig. 2 represents thecurves obtained by plotting the variation of current in the twocircuits, including the coils M and M The horizontal line is thezero-line or L and P.

strength, while horizontal extension represents position of brush D.

Referring to the drawings, A represents a source of electric currents.

13 represents the end view of a current director or distributor, whosefunction is to alternately direct to two coils or electro-magnets 1" andM of engine or tool 0 currents of a pulsatory nature or currentsgradually rising and falling from minimum to maximum. Its organizationis as follows: R R R are three concentric contact rings or plates. R isa continuous plate, to which is connected conductor 1. R and R aresubdivided rings, the adjacent blocks or sections of which are connectedthrough resistancecoils s s s s s s after the manner of rheostats.

The blocks L and P of rings R and R respectively are of. greater widththan the other blocks in the rings. To block N, the middle of the seriesin ring R, is connected conductor 3, while to block K is connectedconductor 4:. The insulated arm E swings around on the post X, and isdriven here by the pulley F, carrying the belt T. The arm E carries thebrush D, that establishes sliding connection between the three rings.The coils s are coils of material of low conducting-power, the coilsincreasing in resistance from the blocks N and K to the blocks P and L,respectively.

The tool 0 consists of two coils or electromagnets, between whichtravels the plunger M. To M is attached the tool The action of thesystem is as follows: Suppose a current to start from the battery A andflow thence through the conductor 1 to the plate R. Thence it passesthrough the brush D to the ring R by way of block K at the instantshown. From block K it flows through conductor 4 to coil M, and throughcoil M to conductor 2, and thence byconductor 2 to battery A, completingthe circuit. Thus it will appear that coil M is energized by a currentof maximums intensely unimpeded by any external resistance, andbar M isdrawn down into coil M i The current at this moment energizing coil M isextremly feeble, since in leaving brush D and passing to block P of ringR the current is compelled to pass through all of the coils s s s s s s,in order to reach conductor 3, connected to block N,and

these coils are in the aggregate of extremely high resistance. Now asthe brush-arm E and brush D revolve around the post X, being driven inany suitable mannerin the direction shown by the arrow, the brush Dmakes contact with the coils s s s successively, and thus graduallyintroduces these coils into the circuit, therebyincreasing theresistance of the circuit and reducing the current flowing through coilM. YVhen the resistances connected into ring B have been largelyintroduced into circuit with coil M and current therein has becomeconsiderably reduced, brush D begins to make contact with blocks in thering R and to cut out the resistance-coils s s 8, connected in this ringfrom the circuit of the coil M and the resultis that the current in thecoil M begins to increase. This action continues, the current increasingin coil M and diminishing in coil M until it has become extremely smallin coil M and a maximum in coil M and plunger M is thus drawn up intocoil M By properly proportioning the resistances s s s s the charactershown by the curves m and m is given to the current in the coils h and MThese curves show the rise and fall of the current in the coils duringthe complete revolution of the circuitcontroller, current starting atZero and rising along the curve, and thus falling to zero again. It willbe noticed that the curves lap so as never to leave the bar M withoutmagnet-ism. An important feature is the arrangement of parts adapted tostart the current in one coil while it still has considerable strengthin the other, as thereby the stroke is cushioned when the tool meets noobject, and, further, the plunger M is never left without anexciting-current, and in consequence its magnetism never falls muchbelow the saturationpoint, and the heating incident to great fluxuationsof magnetism is avoided.

I claim as my invention- 1. The combination, with a source of continuouscurrents, of an electromagnetic reciprocating tool having twoenergizing-circuits, a switch mechanism actuated by a source of powerand adapted to connect the source of continuous currents alternatelywith the two circuits of the tool, and rheostats or variable resistancesbetween the tool-circuits and the switch mechanism, whereby the currentdirected into such circuits is varied in the manner herein set forth.

2. The combination, with a source of continuous currents, a rotaryswitch-lever connected to said source and two series ofcontact-terminals over which the lever sweeps, and artificialresistances through which said contacts are connected, of areciprocating tool having two energizing-circuits connected,respectively, to the series of contacts at or near the middle of thesame, whereby a risin gand falling current will be directed through thetoolcireuits alternately, as set forth.

